Cord reels are well known in commerce at the present time. Generally they comprise a reel mounted for rotation within an enclosing housing. One end of the cord is normally terminated in a socket connector secured to the hub of the reel, the other end to a wandering plug connector. Generally when used only sufficient cord is unwound from the reel to permit the plug connector to be plugged into a close by convenience receptacle, and often the cord may be used with a significant number of turns of cord wound on the reel. The normal electrical rating of cords assumes their use in a linear, free air condition. When cords are used coiled on an enclosed reel, appreciable heat is generated due to resistive and inductive effects. For this reason cords stored on cord reels are required to be derated in current carrying capacity. Typically a cord of 8 m. length having a free air rating of 15a will be derated to about 10a when used with a cord reel. A 30 m. length of this cord would have so low a current rating when forming part of a cord reel as to be of very limited use. Conversely a 30 m. cord reel having a current rating of 15a would have considerable bulk and cost, and again would be of limited use. Moreover, it is required in certain jurisdictions to incorporate into the cord reel a current limiting device to limit the maxium current of a cord used with a cord reel to be derated value of the cord, thereby increasing the cost of the cord reel.
One of the prime potential uses of a 30 m cord reel is as an extension cord for lawn mowers. However, present cord reels, even if the cord stored thereon were of sufficient length and current carrying capacity, are not well adapted to this use, for the receptacle of present commercially available cord reels is normally provided in the hub of the reel, which would necessitate the reel itself having to be transported with the lawn mower. Moreover, if not infrequently occurs that an extension cord when used with a lawn mower is damaged by the cutting blade of the lawn mower. In cord reels of known designs, the cords are either of a non-standard type and/or they require electrical wire connections to be made to the reel receptacle. Replacement of a damaged cord may, then, not be within the competence of many persons, or it may necessitate the procurement of a relatively expensive cord replacement.